CI: fix macOS arch for Apple Silicon runners (#84)

macOS-latest runners are Apple Silicon; setup-julia v3 errors when
`arch: x64` is requested there. Configure each matrix to use the
correct native architecture and bump setup-julia to v3.

Author: timholy

.github/workflows/ci.yml

@@ -4,7 +4,7 @@ on:
   - pull_request
 jobs:
   test:
-    name: Julia ${{ matrix.version }} - ${{ matrix.os }} - ${{ matrix.arch }} - ${{ github.event_name }}
+    name: Julia ${{ matrix.version }} - ${{ matrix.os }} - ${{ github.event_name }}
     runs-on: ${{ matrix.os }}
     strategy:
       fail-fast: false
@@ -16,14 +16,11 @@ jobs:
           - ubuntu-latest
           - macOS-latest
           - windows-latest
-        arch:
-          - x64
     steps:
       - uses: actions/checkout@v4
-      - uses: julia-actions/setup-julia@v2
+      - uses: julia-actions/setup-julia@v3
         with:
           version: ${{ matrix.version }}
-          arch: ${{ matrix.arch }}
       - uses: julia-actions/cache@v2
         env:
           cache-name: cache-artifacts
@@ -37,7 +34,7 @@ jobs:
       - uses: julia-actions/julia-buildpkg@v1
       - uses: julia-actions/julia-runtest@v1
       - uses: julia-actions/julia-processcoverage@v1
-      - uses: codecov/codecov-action@v3
+      - uses: codecov/codecov-action@v5
         with:
-          file: lcov.info
+          files: lcov.info